Ac-spring-boot with MongoDB

hi, I am new to ac-spring-boot and trying to build a JIRA plugin with MongoDB as the backend. However, the document is very limited. I looked into ac-spring-boot samples but I got no lucky.

Can someone please help me build a very simple demo project to use MongoDB?
And, it would be great if can share me some tutorial document on how to build a plugin with ac-spring-boot.

I appreciate anyone could help me !

Thanks